I think Barr’s diagram may include a rough geographical axis as well as a temporal axis. It roughly maps West European art on the left and East European art on the right of the page. The red boxes are ahistorical general cultural influences. Had the diagram stretched beyond 1935, it might have opened a space even further to the left to show the movement of abstract art across the Atlantic.

Daniel Feral’s Graffitti and Street Art diagram doesn’t involve this geographical dimension – because pretty much all the developments he traces occurred in New York. Which surely seems *a little bit* one sided.